Utilization of SOHO/MDI/LASCO/EIT observations. A data driven 3-D Magnetohydrodynamic (MHD) model is developed to investigate the non-potentiality of active-region corona and to determine the criteria for “initiation” of solar eruptive phenomena. The important innovation of this model is its ability to incorporate the realistic photospheric dynamics by inputting the magnetic measurements (i.e. emerging and submerging magnetic flux) together with the differential rotation, meridional flow, effective diffusion, and cyclonic turbulence effects to drive the model. The time-dependent projected characteristic boundary conditions are fully implemented. Thus, the effects caused by sub-photospheric dynamics (i.e. convective zone dynamics) can be reflected through the surface boundary condition which does not precisely handle the sub-surface. Hence, this model is the first MHD model to include the challenge of the coupling between the solar interior and corona, because the photopsheric measurements already consists of the effect of convective zone dynamics.
11:15UT |
14:27UT |
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17:39UT |
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Evolution of simulated L ss (bold white line), the background line-of-sight magnetic field contours (the solid and dotted lines represent the positive and negative polarity, respectively), and transverse field vectors (the white arrow is the potential field, the black arrow is the non-potential field) at 1997 Oct 31, 14:27UT, 17:39UT are shown. The simulation started at 11:15UT which is the potential field computed from SOHO/MDI magnetic field measurements for active region AR8100, and L ss = 0 at this time. |
Reference: A Three-Dimensional Magnetohydrodynamic (MHD) Model of Active Region Evolution, S. T. Wu, A.H. Wang and D. A. Falconer, IAU Symposium 226, “Coronal and Stellar Mass Ejection”, (Kenneth Dere, Jingxin Wang and Yihua Yan, eds.) Cambridge University Press, 291-301, 2005